Integration of Servo and High Bit Aspect Ratio Data Patterns on Nanoimprint Templates for Patterned Media

Magnetic recording bit patterned media (BPM) stands as a promising technology to deliver thermally stable magnetic storage at densities beyond 1 Tb/in². High throughput BPM fabrication will be enabled by nanoimprint lithography which relies on a high-quality master template to be able to meet pattern fidelity and low defectivity specifications. Master template fabrication for BPM can be done by e-beam lithography alone or by e-beam directed self-assembly of block copolymers. Incorporating servo features in the fabrication of master templates brings numerous nanofabrication challenges that vary depending on which method is used. Here we demonstrate the fabrication of conventional servo features at 200 Gd/in² using e-beam lithography and we explore some nonconventional servo geometries that are compatible with self-assembly for BPM beyond 1 Td/in².